Nutrition: How Healthy Is Soy Really?

How healthy is soy really?

Although the bean provides a lot of protein, it is not suitable for everyone, mainly due to its isoflavones, which have a hormonal effect.

5 minutes

Particularly popular in Asian dishes - soybeans in the form of tofu.

Particularly popular in Asian dishes – soybeans in the form of tofu.
© dpa/Christin Klose

Whether as tofu, soy milk or sauce: soy has become an integral part of vegetarian and vegan cooking. More and more soy-based milk and meat alternatives can be found in supermarkets. The bean is known for its high protein content. According to the Federal Nutrition Center, this is about 40 percent in dried beans. Ready-to-eat soy products contain about 11 percent protein, which the body can also use very well.

The legume is ideal for a balanced diet to replace the animal protein that is so important, says Stefan Kabisch, doctor of studies at the Medical Clinic of Endocrinology and Metabolic Medicine of the Charité. Anyone who eats different plant proteins can at least have a balanced diet as a vegetarian. However, vegans would need to add vitamin B12.


Study with a salary!

With or without a high school diploma: study dual at BA Bautzen and start your professional life in three years with professional experience and a bachelor’s degree in your baggage!

In addition to protein content, the list of healthy soy components is long: B vitamins, minerals like magnesium, trace elements like iron, and unsaturated fatty acids, including omega-3 fatty acids. However, the bean also contains substances that nutritionists consider in a more differentiated way. This includes isoflavones, which are similar to the female sex hormone estrogen. For this reason, they are suspected of having a “hormonal triggering effect”, as doctor Stefan Kabisch puts it. This means that they can bind to the same estrogen receptors in the body and trigger the same processes as estrogen.

So soy isn’t as healthy as you think?

Healthy people don’t have to worry about normal consumption, says Kabisch. Due to their regulatory form, isoflavones are “most likely harmless, perhaps even helpful.” This was also shown by long-term studies from Asia, where soy has been on the menu for much longer. By the way, isoflavones are also found in smaller amounts in other legumes like chickpeas, lentils, and beans. And yet, soy is suspected of affecting the thyroid. According to the Kabisch doctors, isoflavones can block a specific enzyme in the thyroid gland. It is responsible for building active hormones from inactive precursors. According to Kabisch, if this enzyme becomes inactive, hypothyroidism can develop. Because this effect is so small and not yet clinically relevant, he sees no health risk to healthy people with normal soy consumption. Also, the amount of isoflavones in soy is reduced by about a fifth when it is made into tofu.

However, the legume is not suitable for everyone. People with hormonal diseases such as breast cancer and metabolic disorders should have their diet reviewed by a doctor, says Nicole Schlaeger, team leader for healthy eating and nutrition education at the consumer center in North Rhine-Westphalia. Basically, she advises against substituting dairy and meat exclusively for soy products.

It is important to make sure there is a change and sometimes use oat or almond milk, ideally fortified with calcium. In other cases as well, most nutrition experts recommend caution. Soy milk is not suitable for infants and young children because it has less calcium than cow’s milk and interactions with other hormones are not yet clear. The same applies to pregnant and lactating women. On the other hand, allergy sufferers should be careful, which also applies to other legumes. According to the consumer advocate, people who are allergic to birch, for example, may also overreact to soy. According to Dr. Kabisch, a diet containing soy is also not suitable for gout diseases due to the purine it contains, a metabolic precursor of uric acid. This also applies to other legumes. If you still don’t want to give up soy, just eat it in moderation.

The hormonal effect of isoflavones is also used in dietary supplements intended to help with menopausal symptoms. Because the artificial dose of 40 to 5,000 milligrams is usually much higher than the natural form (in Western Europe one to three milligrams), according to Dr. Stefan Kabisch, the risk of hormonal side effects could also be increased. Women who are prone to thyroid disease in particular should consult their doctor first. Stefan Kabisch advises against self-medication. In addition, reliable long-term scientific data was still lacking.

If you also want to take care of the environment, you should prefer products with an organic seal. This is the only way to control growing conditions. The soy used for food comes mainly from Europe. (dpa)

Great soy famine in the world

  • 80 percent of the world’s beans are processed into flour, which ends up in animal feed troughs as food.
  • According to WWF, production has increased tenfold in the last fifty years, from 27 million tons to 269 million tons.
  • 80 percent of the world’s soy comes from the US, Brazil or Argentina. Huge areas of forest and savannah are being converted to expand arable land.
  • Between 2000 and 2010, 24 million hectares of land in South America were converted to arable land. Unique habitats for plants and animals are lost, fertile soil is destroyed, and water is polluted. Source: WWF

Leave your vote

Leave a Comment

Forgot password?

Enter your account data and we will send you a link to reset your password.

Your password reset link appears to be invalid or expired.

Log in

Privacy Policy

Add to Collection

No Collections

Here you'll find all collections you've created before.